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Thrombi a concern with use of LAA occlusion device
New research on a device for percutaneous left atrial appendage occlusion indicates that more than 15% of patients experienced thrombus formation after implantation, despite being treated with dual antiplatelet therapy.
Further, CHADS2 and CHA2DS2-VASc scores, platelet count and ejection fraction were all risk factors for thrombus formation.
For the study, researchers performed transesophageal echocardiography in 34 patients with atrial fibrillation undergoing implantation of the Amplatzer Cardiac Plug (St. Jude Medical) and receiving DAPT before discharge and after 3, 6 and 12 months.
Three patients had thrombi before discharge, and three more developed it by the end of the 3-month follow-up period. There were no differences in left atrial volume, left atrial appendage (LAA) velocity, spontaneous echo contrast, transmitral gradient or mitral regurgitation between patients with or without thrombi.
Those with thrombi had higher scores for CHADS2 (4.3 ± 1 vs. 2 ± 1.1), CHA2DS2-VASc (6.8 ± 0.8 vs. 5.2 ± 1.3) and pre-interventional platelet count (282.5 ± 84.4/nL vs. 215.9 ± 63.9/nL), as well as a lower ejection fraction (39.7 ± 10.6% vs. 50.6 ± 11.4%). There was no difference in the frequency of factor 2, factor 5 or methylenetetrahydrofolate reductase mutations and genetic variants associated with reduced clopidogrel activity in patients with thrombi.
The unexpected thrombus formation raises safety concerns for the device, the researchers wrote, adding that most thrombi originated from the central screw, which suggest it may need to be modified. They emphasized the need for close follow-up with transesophageal echocardiography and the use of vitamin K antagonists after implantation.
Disclosure: Plicht reports receiving speakers’ honoraria and travel grants from Abbott Vascular.